The present invention relates to an inverted confocal microscope used for the observation of biological sample as well as for metallic and industrial purposes.
An inverted confocal microscope having an objective lens arranged below the bottom of a culture container, such as a petri dish and a flask, has been conventionally used as a microscope for observing, measuring and imaging the dynamic behavior of a biological sample such as a cultured cell.
The inverted confocal microscope of this type for the study of cell biology involves one disclosed by Jpn. Pat. Appln. KOKAI Publication No. 7-035986. This microscope is designed to have a vertical fluorescent light projection tube for observing a fluorescent light arranged so that the fluorescent image of a live cell into which a fluorescent indicator such as for Ca ions or pH is injected. This microscope includes therein an optical path branching optical system to serve a plurality of image pick-up means such as a photographing still camera, a CCD camera having high space resolution and a high-speed image pick-up device having high time resolution in addition to a device for the observation of a sample, and obtains a plurality of image pick-up optical paths besides an observation optical path.
Meanwhile, as an inverted microscope to provide an image of a live cell at high speed, there is disclosed a microscope in which a confocal scanner unit is detachably attached to a microscope main body by Jpn. Pat. Appln. KOKAI Publication No. 5-60980. The microscope disclosed by 5-60980 employs a confocal disk scanner as a confocal scanner unit. The confocal disk used for confocal disk scanner is constructed by coupling a light condensing disk having multiple pinhole openings into which a plurality of microlenses are embedded, to a pinhole disk having a plurality of pinholes formed to correspond to the multiple pinholes.
Here, each of the pinholes formed in the pinhole disk transmits both an illumination light to a sample and a fluorescent light from the sample, and forms a confocal optical system. With this constitution, the optical disconnect effect of the confocal microscope allows obtaining a high-contrast, clear image. In addition, since the microscope uses a rotary disk scanner, it can observe and pick up an image in a real time manner. It is, in particular, desirable to use this microscope for observing and measuring the physiologically dynamic behavior of a cell by picking up the fluorescent image of a live cell into which a fluorescent indicator for, for example, Ca ions and pH is injected, at high speed.
By the way, the confocal scanner unit as stated above is attached to a microscope main body using a C mount adapter. As a specific way to attach the confocal scanner unit to an inverted microscope is, as shown in, for example, FIG. 1A, the confocal scanner unit is attached to one of three optical takeout ports including a straight barrel 101 on an observation lens barrel 100, a left (or right) side port 103 of a lens barrel 102 and a bottom port 104 below the lens barrel 102. Namely, the confocal scanner unit is attached to one of the three ports and a still camera or a small size CCD camera is attached the remaining two ports. FIG. 1B shows a state in which the confocal scanner unit 105 is attached to the respective optical path takeout ports through the C mount adapter.
However, if the confocal scanner unit 105 is attached to one of the optical path output ports stated above through the C mount adapter or the like, the following disadvantages occur.
First, in case of attaching the confocal scanner unit 105 to the straight barrel 101 above the observation lens barrel 100, an observer's eye point is higher than that during ordinary observation and only a monocular lens can be disadvantageously used. Due to this, at the time of observing a confocal image macroscopically, not only an overstrain affects the observer's posture but also it becomes difficult for the observer to operate the microscope and handle the sample during observation.
In case of attaching the confocal scanner unit 105 to the side port 103 on the left (or right) of the lens barrel 102, the confocal scanner unit 105 is attached at a lower position of the side of the lens barrel, with the result that operability deteriorates. In case of macroscopically observing a confocal image with an eye piece fixed to the confocal scanner unit, in particular, the observer is forced to endure an overstraining posture.
In case of attaching the confocal scanner unit 105 to the bottom port 104 below the lens body 102, the confocal scanner is attached onto the bottom of the lens barrel, i.e., the back side of a table on which the microscope is mounted and the operability of the confocal scanner unit is considerably hampered. The macroscopic observation of a confocal image with the confocal scanner unit is particularly quite difficult to make.